What Is a WAF (Web Application Firewall)?

A Web Application Firewall (WAF) is a security system that protects web applications by monitoring, filtering, and blocking malicious traffic. Operating at the application layer, a WAF prevents threats and vulnerabilities that traditional firewalls often miss.

As a critical component of enterprise security strategy, WAFs minimize attack risks, safeguard sensitive data, and offload malicious traffic at the edge—ensuring system stability and website uptime.

Common attacks a WAF can prevent include:

• SQL Injection: Malicious code inserted into input fields to access the database.

• Cross-site Scripting (XSS): Injects scripts into websites to steal cookies and user info.

• File Inclusion: Uploading dangerous files to gain system control.

• DDoS (Distributed Denial of Service): Overwhelming the server with fake requests.

• Zero-day Exploits: Attacks targeting unpatched vulnerabilities.

Overview of Cloud WAF

What Is a Cloud WAF?

Cloud WAF is a web application security service delivered via cloud infrastructure. Businesses don’t need to invest in hardware or manage on-premises systems—simply subscribe, connect your website, and manage security policies through an online dashboard.

Key Advantages of Cloud WAF:

• Fast Deployment: No hardware or software installation needed.

• Low Upfront Costs: Pay-as-you-go or annual subscription models.

• Automatic Security Updates: Providers maintain the latest threat signatures.

• Centralized Management: Configure and monitor security from anywhere with internet access.

• Scalable: Easily handles traffic spikes as your site grows.

Limitations of Cloud WAF:

• Vendor Dependency: Limited deep configuration control.

• Network Latency: Potential delays if servers are geographically distant.

• Shared Infrastructure Risk: Multi-tenant environments may introduce vulnerabilities if poorly managed.

Overview of On-Premises WAF

What Is an On-Premises WAF?

An On-Premises WAF is deployed directly within a business’s data center or internal system. The enterprise is responsible for installing hardware, software, configuring policies, and maintaining operations.

Key Advantages of On-Premises WAF:

• Full Control: Direct access to configuration, data, and security policies.

• Deep Integration: Easily connects with internal security systems.

• Data Sovereignty: Sensitive data stays within the local environment.

• Highly Customizable: Tailor-made security policies for specific needs.

Limitations of On-Premises WAF:

• High Capital Investment: Requires hardware, licenses, and skilled personnel.

• Technical Expertise Needed: Requires experienced IT and security staff.

• Limited Scalability: Expanding protection means upgrading physical infrastructure.

Detailed Comparison: Cloud WAF vs. On-Premises WAF

Which Solution Is Right for Your Business?

Choosing between Cloud WAF and On-Premises WAF depends on your security requirements, budget, IT resources, and overall infrastructure strategy.

Choose Cloud WAF if your business:

• Is a startup or SME with limited budgets and needs rapid deployment.

• Lacks in-house cybersecurity expertise for ongoing operations.

• Runs cloud-native or globally distributed applications.

• Prefers lower operational costs and zero infrastructure maintenance.

Choose On-Premises WAF if your business:

• Operates in finance, healthcare, or government sectors with strict data compliance.

• Has strong IT infrastructure and experienced security teams.

• Needs to integrate with internal monitoring or SIEM systems.

• Follows strict regulatory standards (PCI-DSS, ISO 27001, NIST, etc.).

EVG Cloud – Scalable WAF Solution for Every Business Size

EVG Cloud offers a Cloud WAF solution tailored for Vietnam’s web hosting and cloud ecosystem. It is trusted by thousands of enterprises in e-commerce, finance, education, and media industries.

Why Choose EVG WAF Cloud:

• Comprehensive protection against SQLi, XSS, File Inclusion, Brute Force, DDoS, and more.

• Quick setup with no hardware investment required.

• User-friendly dashboard in Vietnamese with real-time threat alerts.

• Easily upgradable plans without service interruption.

• 24/7 local support by Vietnamese security experts.

Conclusion

Choosing between Cloud WAF and On-Premises WAF is more than a technical decision—it’s a strategic one that reflects your business’s digital transformation and cybersecurity priorities.
If you're looking for a fast, efficient, flexible, and cost-effective solution, EVG WAF Cloud is the ideal choice. With infrastructure located in Vietnam, a local interface, and dedicated support, EVG empowers your business to stay protected against modern cyber threats.

Contact EVG Cloud for expert consultation at (+84) 968206168.